There exists a need for new structural templates to guide the synthetic organic chemist in the design of potential cancer chemotherapeutic agents. Our studies in the isolation and structural elucidation of tumor-inhibitory natural products have yielded an interesting array of novel types of growth-inhibitory compounds. Three of the new and novel compounds are being prepared on large scale by the National Cancer Institute for pre-clinical pharmacological studies in preparation for clinical trial. The specific aim of the continuing project will be to study the structures and chemistry of new tumor- inhibitory compounds isolated from natural sources.